Tourque/Airmass Request System
TORQUE Overview Trionic 8 is a torque/airmass request system, below a brief explanation how it works. This information is derived from the Trionic 8 technical documentation following the T8Suite. Basic Function When the driver (or cruise control for that matter) presses the accelerator pedal he actually requests a certain torque from the system. This value is fetched from the PedalMapCal.Trq_RequestMap. This table holds airmass values for each position of the accelerator pedal and each rpm. Figure 1: PedalMapCal.Trq_RequestMap The system now looks up the current estimated engine output (torque) based on airmass and rpm. This is done through TrqMastCal.Trq_NominalMap. Figure 2: TrqMastCal.Trq_NominalMap When more torque is requested than currently produced, the new requested airmass (mg/c) is fetched from TrqMastCal.m_AirTorqMap using the requested torque and current rpm as input. Figure 3: TrqMastCal.m_AirTorqMap, original In order to create additional effect, this curve can be modified. In Rev007 of Mackans ST1, this table is tuned. When higher torque is requested, additional airmass is provided in the mid-range rpms. Figure 4: TrqMastCal.m_AirTorqMap, tuned by Mackan Torque Limiters The T8 software contains a set of torque limiters to protect the engine, gearbox, breaks, clutch and turbo. TrqLimCal.Trq_MaxEngineTab1 and MaxEngineTab2 These two maps defines the maximum engine output torque per rpm, for 175/200 (Tab1) resp. 150 Hk engines (Tab2) respectively. Figure 5: TrqLimCal.Trq_MaxEngineTab1 original and tuned As can be seen in the above figure, it is limited to 265nm in the original file but increased to 289nm in the tunes done by Mackan. How this shall be tuned of course depends on what your car can handle, and how you want it to behave. When comparing with the below E85 map in Figure 6, it can be noted that the tuned gasoline map is lower that the E85 map. This map can likely be tuned to match the E85 map. FFTrqCal.FFTrq_MaxEngineTab1 and FFTrqCal.FFTrq_MaxEngineTab2 These two maps defines the maximum engine output torque per rpm, for 175/200 (Tab1) resp. 150 Hk engines (Tab2) respectively, when the engine is running E85. Figure 6: FFTrqCal.FFTrq_MaxEngineTab1 original and tuned by Mackan As noted, in the tuned map - the limiters are lowered compared to original. It looks like this may not be desired to do as it actually limits the car compared to what it handles as original. TMCCal.Trq_MaxEngineTab This is the max torque table. Figure 7: TMCCal.Trq_MaxEngineTab orginal and tuned by Mackan It shall be noted that the max torque is set to 320nm in Mackans map, even though the contributing maps only reaches 289. Likely better to stick to original max 300nm for now. TrqLimCal.Trq_NoiseRedLim and TrqLimCal.Trq_AutNoiseRedLim This is the maximum engine torque limit, for manual and automatic gearbox, that comes into effect when the driver is pushing the accelerator pedal to a calibrated level after been driving at 50km/h for a calibrated time (at second gear if manual car), to reduce noise. The reason this exist would (apparently) be to reduce noise. Noise is not a concern when wanting more power, so this is changed from 225nm to 400nm. That is; removed. My Result An aggressive proposal for all *MaxEngine* maps is: Figure 8: Torque limiters in my aggressive tune Maybe 4500 and 5000 rpm shall be set to 320 as well; needs to be tried out. A more sane proposal, based on E85 limits is: Figure 9: Torque limiters in my proposed tune And, following Rev007 of Mackans tune, noise limiters will be removed.